In an interview with the Financial Times, gül said it is no secret that Syria has chemical weapons and that Damascus has old Soviet delivery systems to deploy them. “So in case there is in some eventuality some sort of madness in this respect and some action is taken, contingency planning has to be put in place and this is something NATO is doing,” he said.

Gül's remarks came on a day when the leader of NATO said the alliance will defend its only Muslim member, Turkey, and has “all plans in place” to do so.

Turkey is becoming increasingly concerned about security along its border with Syria, in an area of the Southeast where Ankara is also fighting an emboldened wave of terrorist attacks waged by the Kurdistan Workers' Party (PKK).

"NATO as an organization will do what it takes to protect and defend Turkey, our ally. We have all plans in place to make sure that we can protect and defend Turkey and hopefully that way also deter so that attacks on Turkey will not take place," Secretary-General Anders Fogh Rasmussen said on Monday.

Turkey earlier said it is talking to its NATO allies about the possible deployment of Patriot surface-to-air missiles to guard against a spillover of Syria's conflict. Rasmussen made no specific remarks on the possible deployment of Patriots.

Damascus has not signed a 1992 international convention that bans the use, production or stockpiling of chemical weapons, but officials in the past have denied it had any stockpiles.

Western countries and Israel have voiced fears that chemical weapons could fall into the hands of militant groups as the authority of Assad erodes.

In July, Syria acknowledged for the first time that it has chemical and biological weapons and said it could use them if foreign nations intervened in the uprising against Assad's rule.

Speaking about a series of mortar rounds that fell in Turkish territory in the past few weeks, Gül said he doesn't believe the Syrian shells were intentional but that Turkey definitely cannot tolerate such action and “we give the necessary response.”

Turkey fired back at Syria in what the US called a “proportionate response” after several mortar shells fell in southern Turkish towns bordering Syria.

Gül warned that increase in the influx of Syrian refugees into Turkey could amount to a security risk as Ankara is concerned over the growing presence of PKK-linked groups in northern Syria.

Turkey is also concerned about the possible infiltration of terrorists among the refugees from Syria and the prospects that the eventual toppling of President Bashar al-Assad's regime could lead to the collapse of the Syrian state and the disintegration of the country.

Analysts warn that the civil war could result in the disintegration of Syria if the Alawites retreat to the country's Alawite-populated regions and declare their own state there. Kurds, who are unwilling to support either the regime or the Sunni opposition, have already declared their own rule in the country's northern towns, bordering Turkey.

The Kurdish move has alarmed Turkey, which fears the PKK may find a fertile new ground in northern Syria to step up attacks on Turkish targets.

Gül said at least 150,000 Syrian refugees are residing in Turkey, nearly 30,000 more than the official count, explaining that his figure includes those refugees outside the camps.

He noted that the first and foremost danger was to the Syrian people and this is clearly a situation that cannot continue. “It is a country that is consuming itself,” he declared.